The game was developed by Obsidian Entertainment, a company mostly made up of guys who left Bioware. They wanted to stick to hardcore RPG gameplay, as opposed to what Bioware became lately. They basically invented the choice system and implemented it really well in Alpha Protocol.
I'd say Tibia is fairly obscure. I played it a few years back in a open PvP server (it also had PvE and Hardcore PvP type servers, meaning you have no limit to slaying others) and it was fun. Going outside the safe zone always had me pumped with adrenaline while I was walking through the 2D isometric world. The game might seem weird at first and throw you off, so you'd need to get used to it if you haven't played similar games as it's not your normal MMO. It is, like many other MMOs, fun with friends and very unique in many ways.
If you have a Nintendo DS and like JRPGs I would definitely recommend Radiant Historia. It's a turn-based RPG like most others, with the exception that its battle system features a unique wrinkle. The battles take place on 3x3 grid and position on the grid is the key to being successful. Different skills allow you to push the enemy into different areas on grid to unleash devastating combos. It's kind of hard to explain but it is a fairly unique system that is highly enjoyable.